ABSTRACT
Nonsecretory multiple myeloma (NSMM) is a rare variant of multiple myeloma without monoclonal immunoglobulins in either serum and urine NSMM represents a variant of multiple myeloma characterized by undetectable monoclonal immunoglobulins in serum and urine, and accounts for one to five percent of all cases of MM. The presence of amyloid was demonstrated by the appearance of green polarization color due to Congo red staining according to Romhanyi in polarized light. Performic acid pretreatment as well as potassium permanganate oxidation with and without trypsin digestion served to demonstrate the resistance of the amyloid tumors. Tissue sections of the lung stained with hematoxylin and eosin showed an eosinophilic mass with an anisotropic effect in polarized light. Staining with Congo red induces congophilia and strong birefringence of amyloid with a green polarization color. The plasma cell infiltrates were immunoreactive with the antibody VS38, against the 64D proteine as specific for plasma cells.
